Definitions
We may occasionally use an unfamiliar photographic term in these posts, so we have included these definitions to assist those unfamiliar with the details. If we use a term you don’t understand, please leave a comment so we can improve this site.
Circular Polarization Filter
A circular polarization filter is attached to the front of a lens to reduce light reflections (think of polarizing sunglasses). The filter is rotated to the best angle to reduce reflections from objects or sunlight bouncing around the atmosphere. This enhances photographs by increasing color saturation (resulting in bluer skies and brighter colors) and contrast.
Crop Factor
Crop Factor is a camera sensor’s diagonal size compared to a full-frame 35 mm sensor. It is called this because when using a full-frame lens on a camera with a smaller sensor, the smaller sensor effectively crops out this much of the image. This has the same effect as using a longer focal length lens designed for the camera/sensor. The Crop Factor of our cameras is 1.6 so that a 100mm full frame lens yields the same image as a 160mm lens. One advantage of this relates to the construction of lenses: nearly all lenses are sharpest at their centers, and quality degrades toward to the edges. This means that a cropped sensor effectively discards the lowest quality portions of the image.
Depth of Field
Depth of Field is the distance between the nearest and the farthest parts of a subject (or objects in a scene) that are in acceptably sharp focus in an image. Depth of field can be calculated based on the focal length of the lens, the distance between the camera’s sensor and the subject, and the aperture (lens opening or f/stop). In simple terms, the closer the camera is to the subject, the smaller the resulting depth of field.
Extension Tube
An extension tube is used with cameras and interchangeable lenses to increase magnification, most often in macro photography. An extension tube contains no optical elements – its sole purpose is to move the lens farther from the camera sensor. The farther away the lens is, the closer its focus and the greater the magnification. Extension tubes frequently come in sets with different lengths so that various combinations can be used, as needed.
Focus Stacking
Focus Stacking – A digital image processing technique where multiple images, each with a different part of the subject or scene in focus, are combined in a separate app such as Photoshop or HeliconFocus. The resulting image has a greater depth of field (DOF) than any of the individual source images. This is frequently the only method to achieve a good image in macro photography where the depth of field can easily be only a fraction of an inch.
High Dynamic Range
High Dynamic Range (HDR) – A technique used in imaging and photography to reproduce a greater range of exposure (light and dark areas) than is possible with standard digital imaging or photographic techniques. HDR is very useful for many real-world scenes containing both strong sunlight and harsh shadows.
The goal is to present a similar appearance to that experienced through the human visual system. The human eye, through adaptation of the iris and other methods, adjusts constantly to adapt to a broad range of light present in the environment. The brain continuously interprets this information so that a viewer can see clearly in a wide range of light conditions, a much wider range than any camera can in a single exposure.
In digital photography, the desired result can be achieved by capturing the same subject with multiple exposures, and then combining them using editing software such as Lightroom or Photoshop, or specialized HDR software such as Aurora HDR. The software selects areas that are properly exposed in each of the images and merges them into single image which provides a greater exposure range. In simple terms, the darkest areas would be selected from otherwise overexposed image while the brightest areas would be selected from otherwise underexposed image.
Many newer digital cameras can create HDR images within the camera without the need for external software.
JPEG Image Format
JPEG (Joint Photographic Experts Group) is a commonly used lossy compression of digital images. The degree of compression can be adjusted, which allows a tradeoff between storage size and image quality. JPEG typically achieves 10:1 compression with little perceptible loss in image quality. Digital camera images are commonly saved using JPEG compression algorithms internal to the camera.
Macro Photography
Macro photography is the art of making small things look big. The technical definition is an image where the subject is reproduced to at least 1:1, or that the image on the camera sensor is the same size, or even bigger, than the real-life subject. In general, the term macro photography is used for very close-up photography. My macro lens is 1:1 at it closest focus distance and with the 1.4x teleconverter and extension tubes the reproduction ratio is 3:1.
Panorama
In photography, a panorama is a wide view or representation of a subject (frequently a landscape or vista). It can also apply to painting, drawing, or a three-dimensional model. The motion-picture term panning is derived from panorama.
In digital photography, the most common method for producing panoramas is to take a series of overlapping pictures and merge (or stitch) them together, using specialized software such as Lightroom or Photoshop. To successfully merge multiple images into a panorama, the pictures must be taken from the same position (to avoid alignment errors between adjacent images), and there must be sufficient overlap in adjacent images that the software can identify features common to both; the recommended overlap is about 30%.
Pre-shooting
Pre-shooting becomes available when RAW Burst mode, described below, is selected. When the shutter button is pressed half way, the camera continuously captures and saves RAW files at 30 images per second into the camera’s buffer memory (but not the memory card). When the shutter button is fully pressed, the images from the previous 0.5 second before full shutter release are saved into the memory card plus additional images while the shutter button is fully pressed, until a maximum number of images is saved. All of these images are saved as a single RAW burst file. The camera can be used to select and save individual images from the burst and computer software can also extract and save individual images from the burst.
RAW Image Format
A digital camera’s raw image file contains the complete data from the image sensor intended to capture the information about the light intensity and color of the subject without any processing or compression. It can be considered the digital equivalent of exposed but undeveloped film which can be converted (electronically developed) using software on an external device. RAW image files are preferable to JPEG files for image processing because the totality of the image data provides more information about each pixel in the captured image and allows more flexibility and artistic adjustments to the image. Most image processing software (Lightroom, Photoshop, etc.) routinely handle RAW image files.
RAW Burst
This is a feature of newer interchangeable lens mirrorless digital cameras such as the Canon EOS R7. Using the electronic shutter, when the trigger is pressed half way, the camera continuously captures and saves RAW files at 30 images per second into the camera’s buffer memory (but not the memory card). When the trigger is fully pressed, the images are saved to the memory card. All the shots in the burst are saved in one file instead of separate files for each shot. The camera can be used to select and save individual images from the burst and computer software can also extract and save individual images from the burst. A very useful (but optional) feature associated with RAW Burst is Pre-shooting, described above.
Teleconverter
A teleconverter is a second lens mounted between a camera and its interchangeable lens which increases the effective focal length of the lens by enlarging the central part of the image obtained by the lens.
Software and Apps
I use a number of apps on my 27″ iMac computer and my smartphone to assist with the photography process. I will mention them here in case anyone is interested in using them.
Aurora HDR
Aurora HDR is computer software created specifically for editing High Dynamic Range (HDR) images. It can be used as a stand-alone editor or as a plugin to Lightroom so photos in Lightroom can be combined in Aurora directly, without having to save Lightroom edits, open and combine them in Aurora, save the result, and then import it into Lightroom.
Geotag Photos Pro
When turned on, this smartphone app periodically records my GPS location and time and uploads it to a website to create a trip log. Using a corresponding app on my computer, the app will read the website data and add the GPS location to the metadata of matching photos saved on the computer. Configurable settings control the minimum distance between tagged locations and how frequently locations are saved. The app supports multiple ways to save and access the data.
HeliconFocus
HeliconFocus is computer software used in stacking a group of images (Focus Stacking). It works much better and faster than Photoshop, the file size of the resulting images is smaller, and the developed images typically are sharper, have better color, and have less noise than those from Photoshop. It can be used as a stand-alone app or as in conjunction with Lightroom so photos in Lightroom can be combined in HeliconFocus directly, without having to save Lightroom edits, open and combine them in HeliconFocus, save the result, and then import it back into Lightroom.
Lightroom
Lightroom is an image management and editing program developed by Adobe (the same company that created Photoshop). Using Lightroom, photographers are able to organize, sort, and process their images, and eventually export for printing and sharing. One major advantage of Lightroom is the image edits are non-destructive — they are saved as a series of commands in a small text file that is applied when the image is displayed, printed, or exported. Thus, any change can be easily reversed and multiple versions of the same image with different edits can be made without using significant disk storage. In addition to more common image editing tools (e.g. exposure, contrast, color correction, sharpening, noise reduction), Lightroom is able to merge multiple images into a panorama, merge multiple exposures into an HDR image, and combine multiple images taken at multiple exposures into an HDR panorama in one step.
Moon Seeker
This smartphone app shows the path of the moon (compass direction and elevation) for any city or GPS location and any date. For the selected date and location, it also displays the % illumination and the next phase of the moon.
PhotoPills
PhotoPills is a smartphone app for planning photographs ahead of time It helps you be at the right place at the right time to capture the best possible photos. Visual and map data are available for sun, moon and milky way locations and paths including an augmented reality that superimposes the sun, moon, or milky way on the desired subject to help determine the optimal location and time for the desired photograph.
Photoshop
Photoshop is a photographic image editing program developed and published by Adobe. It was originally created in 1988 and has become the industry standard not only in image editing, but in digital art as a whole.
Photoshop’s basic functionality can be extended by add-on programs called plugins which typically provide a specific functionality. most plugins are developed by third-party companies.
Photos Exif Editor
This computer app allows me to edit the Exif data associated with a digital camera image. This data can include camera and photograph information such as camera make and model, lens make and model, camera exposure data, date and time, and metadata such as keywords, copyright information, image title and description, image size, and GPS location.
rGPS (Really Good Photo Spots)
This smartphone app helps photographers find great photography locations near them, search for locations in distant locations, add their own locations, and share photos of the best spots. Shared photos are geotagged and reviewed by professional photographers who rate the photos and confirm the GPS coordinates.
Sol: Sun Clock
Sol is a smartphone app that identifies the time of multiple light conditions for any day and location. The conditions identified are Morning, Solar Noon, Afternoon, Golden Hour PM, Civil Dusk, Nautical Dusk, Astronomical Dusk, Solar Midnight, Astronomical Dawn, Nautical Dawn, Civil Dawn, Golden Hour AM.
Starry Landscape Stacker
This computer app is for making images of the night sky with stars and reducing noise. Digital noise in digital photography is similar to grain in film photography. High speed (high ISO) films were grainier than low speed films. It uses “stacking” or “image averaging” to combine a group of images that were captured in rapid succession with identical exposure settings and the camera in a fixed position. The result is an image with stars and much less noise than you could achieve with a single exposure. It works because digital noise in an image is random, so averaging multiple exposures reduces the noise in the final image. The app recommends 10 exposures minimum and 20 exposures preferred.
Sun Seeker
This smartphone app shows the path of the sun (compass direction and elevation) for any city or GPS location and any date. For the selected date and location, it also displays the shadow ratio and path length.
Topaz Labs
I use four computer software programs from Topaz Labs: Topaz DeNoise AI, Topaz Sharpen AI, Topaz Gigapixel AI, and Photo AI. All of these programs use very specific Artificial Intelligence algorithms to perform their functions. Each of these programs works either as a standalone program or as an add-on external editor for Lightroom and Photoshop and each has a specific purpose related to its name – DeNoise AI reduces noise in images, Sharpen AI sharpens fuzzy or blurry images, and Gigapixel AI increases the size of an image without adding blur and noise or pixelating the image; Sharpen AI and Gigapixel AI also reduce noise while they perform their primary function. Photo AI is the newest program and easily provides good results. It combines the functions of the other three programs into one application but without the best possible results which can be achieved using the individual programs.